RFR: 8346567: Make Class.getModifiers() non-native [v2]

[Dean Long]

On Wed, 5 Feb 2025 19:42:02 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> test/micro/org/openjdk/bench/java/lang/reflect/Clazz.java line 73:
>> 
>>> 71:     public int getAppArrayModifiers() {
>>> 72:         return clazzArray.getClass().getModifiers();
>>> 73:     }
>> 
>> I'm guessing this is the benchmark that shows an extra load.  How about adding a benchmark that makes the Clazz[] final or @Stable, and see if that makes the extra load go away?
>
> Name                      Cnt  Base   Error   Test   Error  Unit  Change
> getAppArrayModifiers       30 0.923 ± 0.004  1.260 ± 0.001 ns/op   0.73x (p = 0.000*)
> getAppArrayModifiersFinal  30 0.922 ± 0.000  1.260 ± 0.001 ns/op   0.73x (p = 0.000*)
> 
> No it doesn't really help.  There's still an extra load.

OK, if the extra load turns out to be a problem in the future, we could look into why the compilers are generating the load when the Class is known/constant.  If the old intrinsic was able to pull the constant out of the Klass, then surely we can do the same and pull the value from the Class field.

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PR Review Comment: https://git.openjdk.org/jdk/pull/22652#discussion_r1943616021